The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Turf maintenance vehicles (i.e., grounds keeping vehicles) are used for used for various tasks, such as cutting grass, fertilizing soil, and the like. These vehicles can include one or more electrically-powered subsystems. For instance, some mowers include electrically-powered ground traction subsystems for propelling the mower, electrically-powered cutting implement subsystems for cutting grass, electrically-powered steering subsystems for steering the vehicle, and/or electrically-powered accessory subsystems for illuminating headlamps, gauges, and the like. Turf maintenance vehicles of this type are disclosed, for instance, in U.S. Pat. No. 6,571,542, U.S. Pat. No. 6,938,400, U.S. Patent Publication No. 2005/0230168, U.S. Pat. No. 6,729,114, U.S. Pat. No. 6,857,253, U.S. Pat. No. 6,644,004, U.S. Pat. No. 6,449,934, U.S. Pat. No. 6,082,084, and U.S. Pat. No. 5,794,422, each of which is incorporated by reference in its entirety.
These subsystems can be electrically powered by a variety of power sources. For instance, some turf maintenance vehicles include an internal combustion engine (ICE), such as a gas or diesel engine, which is operatively connected to an energy converting device (ECD), such as an alternator or a generator. The ICE creates mechanical energy from combustion of fuel, and the ECD converts the mechanical energy from the engine to electrical energy. The electrical energy from the ECD is used to power one or more of the sub-systems of the vehicle. Typically, these vehicles also include a voltage regulator that regulates voltage from the ECD to maintain proper operation of the subsystems.
However, the engine speed range remains constant (e.g., between 2700 RPM and 3100 RPM) regardless of the electrical demand of the subsystems. Thus, even when the electrical demand is low, the ICE may still operate at a relatively high speed. As such, the ICE burns fuel excessively and the ICE makes excessive noise. Also, even when electrical demand is high, the ICE may operate at too low a speed, and the electrical demand may not be adequately met by the ECD.